Large crowd at the Expo event for Lego (held at the "Dulles Expo" convention center in Chantilly Virginia)
Quite a few Lego fan clubs with exhibits from membership. Mostly childrens work, but quite a few adults with impressive constructions, some so large they towered a good twenty feet into the air.
Many variations on iconic pop-media items (Star Wars, especially).
Though there were mainly Northern-Virginia family groups at the event, many young males were in attendance too, either exhibiting or taking pictures of the exhibit items.
There were signs noting that customized lego pieces were used for many of the exhibit items, meaning that some self-creation/alteration of lego pieces was necessary to create some of these amazing pieces.